Oh stop being a paranoid dipshit. HEPA filters are well understood, aren't made by this guy, and have been being tested by hospitals for fourty years.
"OMFG he claims a hepa filter does what hepa filters do??!!?!? WHY SHOULD WE BELIEVE IT"
Because it's pretty obviously a sensible claim. Duh. Go to Target, spend the $20 it would take to try it yourself, and please grow up a little bit.
I mean seriously, what kind of person thinks putting an air filter in front of a fan doesn't actually filter air? Seriously.